Resource interpreted as Stylesheet when using JetPack Custom css

Hi there,

I am getting this error only when I turn WP Super Cache on my website. I am running a multi site.
Here’s the error:
Resource interpreted as Stylesheet but transferred with MIME type text/html: "http://mydomain.com/?custom-css=10f89e2811"

I am using JetPack for adding my custom css. The custom css works when WP Super Cache is turned off but when I turn WP Super Cache on, the custom css is not getting applied and this error is seen in the console.

When the website loads, the stylesheet is getting rendered as a text/html type instead of css.

How can we fix this?

Regards,
David.